Sighting device for naval guns



w. AKEMANN SIGHTINGl DEVICE FOR NAVAL GUNS Filed Jan. 5.. 1921 Fig/1.

2 Sheets-Sheet 1 May1s,1924. 1493588 w. AKEMANN SIGIITING' DEVICE FOR NAVAL GUNS Filed Jan. 5. 1921 2 Sheets-Sheet 2 Patented May i3, 1924.

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PATENT OFlCE..`

WALTHER AKEMANN, 0F ESSEN, GERMANY, ASSIGN'OR. TO FRIED. KRUPP AKTIEN- GESELLSCHAFT, OF ESSEN-ON-THERUHR, GERMANY.

Application med January 3,' 1921.

Serial No. 434,632.

(GRANTED 'UN'DER THE PROVISIONS 0F THEAGT 0F MARCH 3, 1921, 41 STAT: L., 1313.)

To all whomy t may concern.'

Be it known that I, WALTHER AKEMANN, residing at Essen, Germany, a citizen of the German Republic, have invented a certain new and useful Improvement in Sighting Devices for Naval Guns, for which I have filed applications for patents as follows: Germany, Dec. 15, 1916; France, Dec. 8, 1920; Great Britain, Dec. 7, 1920; Japan, Dec. 29, 1920; and of which the following is a specification.

This invention relates to a sighting device having a stabilizing gyroscope and intended for use with naval guns and provided with a telescope having a bent opti,-

cal axis and in the case of which a gyrog scope of only comparatively slight capacity is required even when a large size telescope is being made usey of.

The invention will be described with reference to the accompanying drawing which illustrates, as an embodiment of the sub ject matter of the invention, a sighting device located in the conning turret of a vessel and connected to the transmitter oi' a long-distance controlling apparatus rfor the guns and having a telescope formed by a periscope.

In this drawinge Fig. l is a side view of the sighting device with the pertinent parts of the conning turret disclosed in vertical section,

Fig. 2 is a longitudinal mid-section through the periscope shown in Fig. 1 and forming a part of the sighting device, along with the immediately contiguous parts of the conning turret, and` Fig. 3 is a detail view, partly in section on line 3 3 in Fig. 2.

Referring to these drawings, A denotes the fixed conning turret of a man-of-war, B an armoured cupola of circular cross section mounted to rotate on ball bearings within the root al of the turret, a sight opening 711 being formed in the side wall ot the said cupola. The lower end of the armoured cupola B, which projects through an appropriate opening into the interior of the turret, is closed by a bottom b2 adapted `to prevent fragments of shells or the like,

ed to rotate within a support a3 fixed to the roof al, while its shaft carries a pinion ci* meshing with a toothed wheel b3 arranged at the lower end of the cupola B. `This toothed wheel b3 gears further with a second toothed Wheel a5 rigidly fixed to the rotor shaft yof a transmitter AG belonging to a long-distance controlling device for the traversing gear of a gun. The transmitter A6 is lmounted on the side wall of the turret A inthe manner illustrated in Fig. l. By the abovementioned connection between the armoured cupola B and the transmitter A6 of a long-distance controlling device for the traversing gear of a gun the object is obtained that when the cupola B executes a rotary motion, the revoluble part of the transmitter A6 will rotate about an angle Vproportional, to this motion, and that the said part of the transmitter A6 will transmit its rotation upon the traversing gear of the gun in such a manner, that this latter, too, will be obliged to turn about an angle equal to the angle of rotation of the cupola B.

The bottom b2 of the cupola B serves at the same time as the seat for an yupright `periscope (see in particular Fig. 2). The

said periscope consists 1n the customary manner of a top portion C containing the admission lens c1 and the refracting prism c2, a central portion C3 revoluble relatively to the portion C and serving as a support for a tube 09 containing the erecting prism c7 and the object ylens 08 as also the pinions @11 and cl2 of the erecting prism c7 'and finally a bottom portion C6 containing the roof-shaped inverting prism ct and the eyepiece c5. The top portion C- supporting the admission lens c1 and the refracting prism c2, is rigidly connected in the manner shown in Figs. 1 and 2 by means of a set screw b4 with the bottom b2 of the cupola B, so

ywall of the armoured cupola B.

that it is forced to participate in every rotary motion executed by the cupola B and this in the like sense and with the like angular velocity, whereas the central portion C3 supporting the pinions 011 and cl2 of the erecting` prism c7 is rigidly connected by means of a set screw a7 with the support a3 fixed to the roof al of the turret A, so that the angular position of this portion C3 will not'be chang-ed by a rotation of the cupola B. The arrangement devised is such that the bottom portion CG of the periscope, containing the eyepiece 05, is located underneath the bottom g'and therefore within the interior of the turret A, while the top portion C, which is intended to be focused on the object to be fired at, projects into the cupola B and is disposed with its admission lens `01 opposite the sight opening b1. The top portion C is connected to the tube 09, disposed to rotate within the central portion C3 and carrying the erecting` prism c7 and the object lens cs, by means of a toothed gear 01 c cl2 cl3 in such wise that in the course of a rotation of the top portion C which participates in a rotation of the cupola B, the tube 09 will revolve relatively to the central portion C3, which is fixed in its position by the support a3, in the like direction but with half the angular velocity of the top portion C. The bottom portion C6 carrying the eyepiece c5 is loosely revoluble relatively to the central portion C3.

The refracting prism 02 is mounted to rock about a horizontal axis within the top portion C by intervention of a mounting 014 shaped to form a fulcrum; the said axis being disposed transversely to the rays entering through the admission lens c1. The mounting 014 is provided at a portion of its shell surface with a series of teeth 015 which the teeth of an intermediate wheel (cm), lodged in the top portion C, are adapted to engage. A toothed sector (Z3 gears with the intermediate wheel 016; the said sector being likewise disposed to rock within the top portion C by means of a shaft d2, for its part arranged in parallel to the axis of rotation of the mounting 01". One end of the shaft (Z2 extends beyond the top portion C of the periscope and is rigidly connected with the coaxially disposed outer Cardan shaft Z1 of a stabilizing gyroscope mounted by means of a Cardan suspension within a casing D (Figs. l and The Cardan shaft (Z1 forms the material axis stabilized by the gyroscope. The casing D is rigidly mounted on a-pedestal b5 fixed to the inner rl`he arrangement and the ratio of transmission of the toothed gear (Z3 om 15 interposed between the Cardan shaft all and the refracting prism 02 is so determined that, in the case of relative movements executed by the Cardan shaft Z1 fixed in the space by the gyroscope, the angle of rotation of the refracting prism c2 with respect to the top section C will only be about one half of the angle of rotation of the Cardan shaft d1 with respect to the casing D and that this first-named angle has the same direction as this latter angle of rotation.

The manner of operation of the device is as follows:

The man stationed in the turret and appointed to sight the object places one eye against the eyepiece of the bottom portion CG and by rotating the hand wheel a? causes the cupola B to be revolved until the object to be sighted is visible within the reticule of the periscope so that, as a result, this latter will bei laterally focused upon the object. At the same time the aforesaid rotation of the hand wheel t2 causes by intervention of the gear a* 223 a5 such a rotation of the adjustable part of the transmitter A of the long-distance controlling device that likewise the gun to be pointed will be laterally trained upon the object. Now in the event of the vessel executing a rolling motion so that, for example, the ships deck will swing for an angle or relatively to the horizontal position, then, on the one hand, the periscope will, as an entirety, be likewise revolved for the angle a relatively to its upright position disclosedin the drawing; while, on the other hand, in view of the` fact that the Cardan shaft l1 retains its position in the space by the action of the gyroscope while at the same time executing a relative motion for the angle cc relatively to the gyroscope casing D, the refracting prism c2 will be caused to revolve by intervention of the gear d3 c 015 relatively to the top portion C in the same direction of rotation for the angle The aforesaid rotation ot the the invention makes it possible to keep even when employed in combination with a periscope (the particular utility of which latter for war purposes has been generally acknowledged), the line of sight parallel to itself when the ship is rolling and this by Y means of a stabilizing gyroscope of coniparatively slight capacity. This advantage is based upon the fact that with the sighting device according to the invention the mass, formed by the refracting prism 02 and its driving gear, and Which is to be rotated by the gyroscope when the vessel is rolling, is comparatively very small relatively to the mass of the entireperiscope, so that, consequently, a stabilizing gyroscope of but only slight capacity will .develop` a sufficiently large directive force.

A further advantage of the described sighting device is that the man sighting the object to be fired at is enabled to press his eye against the eyepiece of the bottom portion C6 of the periscope Without any liability of the pressure thus brought to bear on the periscope causing any undesirable displacement of the gyroscope. i

But beyond this, a most important advantage of the form of execution of the sighting device hereinbefore explained will be found to consist in the possibility created of restricting to a minimum the dimensions of the armoured cupola B serving to lodge the periscope and the gyroscope and consequently also the power required to rotate the cupola and further of the general arrangement being devised in such a manner that the man appointed to sight the object'vvill be able to remain Within a splinterproof compartment and Will therefore be enabled to observe the object undisturbed and Without being obliged to change his position.

Having now particularly described and ascertained the nature of my said invention, and in What manner the saine is to be performed, I declare that what l claim is:

l. In an arrangement of the class described, a sectional telescope, a reflecting means in one end section of' said telescope, means for rigidly supporting the center section. of said telescope, said sections being rotatable relatively to each other, a s'tabilizing device connected to said reecting means for stabilizing the same, said stabilizing device being rotatable with the end section carrying said reflecting means.

2. In a sighting device of the class describeda telescope having a bent optical axis, said telescope being formed in relatively rotatable sections, a reflecting means supported Within the upper section, the central section being xed, a stabilizing gyroscope, means operatively connecting said gyroscope to said reflecting means to cause said reflecting means to rotate relatively to the section of the telescope supporting it, when the vessel is rolling at half the angular velocity and in the same direction as the stabilizing device. and means for supporting said stabilizing device for rotation with thel section of telescope containing said reflecting ineans.

3. 'An arrangement of the class described comprising a conning turret, a cupola` revolubly mounted on said turret, a telescope supported by said cupola, saidtelescope being formed in sections, the top section tliereof rotating With said cupola, a reflecting mjeans supported in the upper section of said telescope, means for rotating said cupoyla and means for stabilizing` said reflecting means.

e. A sighting device of the class described comprising a conning turret, a cupola rotatably mounted on said turret, means for rotating said cupola, a telescope supported in said cupola, said telescope being formed in sections, the top section thereof being fixed to the cupola Jfor rotation therewith, means rigidly securing the central section of the telescope to the turret, a reflecting` means carried by the top section of the telescope, an erecting prism carried b y the central portion of said telescope, and a gyroscope carried by said cupola for automatically stabilizin(y said reflecting means.

5. A sighting device of the class described comprising a conning turret, a cupola rotatably mounted on said turret, means for rotating` said cupola, a. telescope supported in said cupola, said telescope being formed in sections, the top section thereof being fixed to the cupola for rotation therewith, a reflecting means carried by the top section, means rigidly securing the central section of the telescope to the turret, a tubular .member rotatably mounted in said central section, an erecting prism and object lens carried by the tubular member, means connecting the tube to the top section of the telescope to cause it to rotate in a like direction but with half the angular velocity of the top section, and a gyroscope carried by said cupola. for automatically stabilizing said reflecting means. y

6. An arrangement of the class described comprising a conning turret, an armored cupola rotatably mounted on said turret, means for rotating said cupola, a periscope supported in said cupola, so positioned that the lower port-ion thereof projects into said turret, a reflecting means carried by the upper portion of said periscope. a gyroscope operatively connected to said reflecting means, for stabilizing the same. said gyroscope being supported iii said cupola.` substantially as described. v

7. An arrangement of the class described comprising a conning turret, an armored cupola revolubly supported on said turret, a bottom for said cupola, means for rotating said cupola, a transmitter forming part of a long distance controlling` device operatively connected to said cupola, a sighting telescope supported by the bottom of said cupola and projecting into said cupola and into said turret` said sighting telescope being formed in sections. the upper section thereof being fixed to rotate with said cupola, means rigidly securing the central section of said telescope to said turret, the

lower section of said telescope being freely Essen, Germany, this 21st day of October, rotatble, a` stablizable reflecting means oa-r- 1920. red the upper section of said telescope, y meansyfor stabilizing said means, said sta- DR' WALTHER AKEMANN' JS blizing means being supported in said In presence ofoupola. HANS, Gor'rslsrANN, The foregoing specification signed at JOHANN DECKERS. 

